/*  
 *  Copyright 2006 Paul Jack.
 *
 *  This file is part of the Dex compiler suite. 
 *  
 *  Dex is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the
 *  Free Software Foundation; either version 2 of the License, or (at your
 *  option) any later version.
 *  
 *  Dex is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 *  Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */
package dex.compiler.interpreter.value;


import dex.compiler.checker.type.BooleanType;
import dex.compiler.checker.type.IntegerType;
import dex.compiler.checker.type.Type;


/**
 * Utility class for determining 
 */
public class Defaults {


	/**
	 * Utility class, do not instantiate.
	 */
	private Defaults() {
	}


	/**
	 * Returns the default value for the given type.
	 * For integer types, the default value is zero.
	 * For the boolean type, the default value is false.
	 * For reference types, the default value is null.
	 * And I should really figure out what the default
	 * value for local member types is.
	 * 
	 * @param type  the type whose default to return
	 * @return  the default value for that type
	 */
	public static Value get(Type type) {
		if (type == BooleanType.INSTANCE) {
			return BooleanValue.FALSE;
		}
		if (type instanceof IntegerType) {
			IntegerType it = (IntegerType)type;
			return new IntegerValue(it.isSigned(), it.getWidth(), 0);
		}
		if (!type.isLocal()) {
			return NullValue.INSTANCE;
		}
		// FIXME: Implement this
		throw new UnsupportedOperationException();
	}

}
